In a metallurgical furnace (e.g., a blast furnace), cooling elements are typically provided to protect a lining or layer located between the burden and an outer shell of the furnace. For instance, in a blast furnace, the cooling elements (i.e., copper staves) may be used in the lower part of the stack, the belly, the bosh, and/or the hearth portions. The staves are, in part, intended to provide a heat removal or dispersal function by circulation of a coolant, through passages therein.
However, as is well known in the art, the staves deteriorate over time, and their cooling effectiveness deteriorates accordingly. In the harsh environment of the metallurgical furnace, the staves are subject to erosion or other damage to the extent that the staves are ultimately removed, in whole or in part. Typically, the cooling function of the staves continues until one or more of the passages therein are exposed, and the coolant ceases to circulate. This in turn may lead to overheating of the outer shell, requiring prompt repair.
The erosion of the staves may be localized, or it may be more general. If the staves' coolant passageway is breached, then the coolant's circulation must be shut off or significantly reduced, to avoid damage to the refractory lining and a possible catastrophic explosion. In these circumstances, it is necessary to either reduce output significantly, or to blow down the blast furnace, to remove and replace the damage stave or staves.
Replacement of staves and/or the refractory lining requires the metallurgical furnace to be shut down for a lengthy period of time. The production lost as a result typically represents a very large financial loss.